In a small bowl, stir together the syrup, almond butter, salt and vanilla until combined. Gently fold into nut mixture until completely incorporated. This mixture is very sticky. Spray your hands lightly with cooking spray to help manage the mixture. Transfer mixture evenly into prepared baking dish.

Spray the bottom of a drinking glass with cooking spray. Press down mixture and pack into the pan. Be sure there are no air pockets.

Bake 15 minutes. Remove from oven and allow bars to cool completely in pan on a wire rack. Refrigerate or freeze for faster cooling.

Lift cooled bars from pan with the parchment paper. Cut into 12 rectangles with a serrated knife. Remove bars from parchment and wrap individually in plastic wrap. Refrigerate in an airtight container for up to two weeks.